1. Field of the Invention
The present invention relates to a stereo photographic system comprising a stereo camera, a stereo slide mount and peripheral equipment. More particularly, the invention relates to a stereo photographic system which facilitates the mounting operation and correctly reproduces a stereo image.
2. Description of the Prior Art
When the two frames of stereo photographic reversal films are to be mounted on a stereo slide mount, attention must be given to a positional relationship between the right and left films. In particular, it is important to so adjust the mounting offset of the films that a subject that most seriously affects the matching between the right and left pictures (degree of effect varies depending upon the size, position, color, contrast of a subject, and, particularly, a subject in a close-range view affects greatly) is located at equal positions in the right and left pictures.
When the films are mounted on proper positions, a natural three-dimensional view is obtained when the films are viewed using a stereo slide viewer. When the positions of the subject that most seriously affects the matching are not in agreement between the right and left pictures, however, a person finds an offensive feeling when he views the image accompanied by serious feeling of fatigue.
Due to a difference in the visual fields of the right and left photographing lenses of the stereo camera, furthermore, a pair of right and left reversal films photographed by a stereo camera develop a non-overlapping portion in which the photographing regions are not in agreement at the outer edges of the pictures on the right and left films. In the non-overlapping portion, no three-dimensional image is formed despite it is viewed using the stereo slide viewer. When a stereo photograph without masking the non-overlapping portion is viewed by two eyes, a vertical line on which the edge of another window is superposed appears on a boundary between the overlapped portion and the non-overlapped portion to impair the interest. In order to prevent this, therefore, it has been attempted to form the windows of the stereo slide mount having a width smaller than the width of the pictures on the films, and to place the subject that most seriously affects the matching of the right and left pictures at nearly equal positions on the right and left pictures of the stereo slide mount by masking the non-overlapping portion.
The ratio of the non-overlapping portion occupying the picture increases with a decrease in the photographing distance. Therefore, plural kinds of stereo slide mounts having stepwisely changing window widths are prepared, and the films are mounted by selecting the one having a window width that is considered to offer an optimum masking amount.
However, it is not easy to judge by eyes a suitable picture-masking amount of the films or the offset amount, and there are frequently found stereo slide amounts offering unnatural stereo effect due to the films that are mounted in an undesirable state.
Therefore, there arises a technical problem that must be solved to provide a stereo photographic system that makes it possible to judge the positions for mounting the films on the stereo slide mount, to judge a suitable picture-masking amount, and to easily execute the mounting operation. The object of the present invention is to solve the above-mentioned problem.